Toxoplasma gondii risks and transmission in cats

Toxoplasma gondii is a single-celled protozoan parasite that utilizes felids as its definitive hosts, meaning cats are the only animals in which the parasite can complete its sexual reproduction phase and shed infectious oocysts in their feces.

While many cats exposed to the parasite show no symptoms, infection can lead to fever, lethargy, respiratory issues, and neurological signs, particularly in kittens or immunocompromised animals. In humans, the parasite is known to cause clinical issues including miscarriage and neurological disease. Most indoor cats rarely shed the parasite, and risks to pregnant individuals can often be managed through hygiene practices, such as avoiding litter box duties.